Interest Income and Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest Income Expense Net [Abstract]
Loans held for investment, net	$ 121,337	$ 87,239
Investment securities	34,262	29,952
Margin balances	6,912	6,091
Financial instruments owned	5,420	2,895
Other	2,496	(1,363)
Total interest income	165,435	127,540
Senior notes	11,425	12,103
Bank deposits	929	1,283
Other	(2,897)	(1,054)
Total interest expense	$ 9,457	$ 14,440